I am the owner of an E-M5 which I use a lot and I have some concerns about where I am going. Rather rashly I sold an E5 to purchase the E-M5 and realised too late that I should have planned my move into M4/3 more wisely. Leaving aside the problems I have had using some of my 4/3 lenses with the E-M5 I am still hoping that I am going to be able to assemble a complete system using M4/3. However development seems to have slowed down a little which concerns me somewhat. So here are a few questions that someone, especially the manufacturers, may be able to answer:

Is there any likelihood, in the foreseeable future, of seeing same brand extension tubes on the market, or same brand teleconverters, or same brand super-telephoto primes, or underwater housings? Is Olympus ever going to produce an E-Mx with a built-in flash?

Bearing in mind the superb sensors in the latest offerings, when will photography of FAST-moving objects ever be a possibility? When will low-light AF be as reliable as it was with my E5?

A lot of questions I know, but for me to see a way forward to stay with M4/3rds they are all fairly crucial.

Hi David. Compact System Cameras (mirrorless interchangeable lens digital cameras) have only been around since 2008, less than five years. Micro Four Thirds is the leading CSC platform with more bodies and variation in body type and many more lenses than any other CSC platform. CSC is growing and sales of DSLRs in many regions are flat or in decline. CSCs already equal unit sales of DSLRs in Japan, for example and will surpass DSLRs some time this year (if not already) according to the long term trend.

It's true that CSCs do have some weaknesses, like autofocus tracking fast moving objects - birds in flight being a good example. And while it may be the case that development has slowed, it was originally at a furious pace that was always going to be difficult to sustain.

But let's look at the specific points you raised:

Same brand extension tubes? I would guess that Panasonic and Olympus will produce extension tubes at some time in the future; they have produced macro lenses, so extension tubes seems like a logical addition. But in any case Kenko already produces Micro Four Thirds extension tubes with full electronic pass-through. You can also use the Olympus EX-25 extension tube with a Micro Four Thirds/Four Thirds adapter when using Four Thirds lenses.

Teleconverters. So far there has been little incentive to produce Micro Four Thirds teleconverters because there are relatively few long and fast Micro Four Thirds lenses. You can of course use Four Thirds converters with Four Thirds lenses. The question is whether or not we will ever see fast long lenses because these will be relatively large and heavy, something that contradicts the basic attraction of Micro Four Thirds in being relatively small and light. But I am optimistic that we will eventually see faster long lenses and last year's introduction by Panasonic of the 35-100 (70-200 equivalent) f/2.8 reinforces my optimism.

Low light AF. Panasonic has already tackled low light AF with its new GF6 and G6 models. These strategically reduced the focus speed in low light, which is extremely fast in normal light (faster than DSLRs), to improve focus lock reliability and accuracy - and it does seem to work.

Fast moving subject AF. This is the toughest challenge of all, I think. But I don't think it is insurmountable. Olympus has already (and repeatedly) promised a camera that will focus Four Thirds lenses properly - and by that I read that these lenses will work as well, maybe better, than a DSLR. All the signs are that Olympus will release this camera before the end of this year. The only question will be if it is a Four Thirds-only camera (maybe a conventional DSLR) or if it will be a more ambitious Micro Four Thirds camera that can be adapted elegantly to take Four Thirds lenses. None of this really answers whether or not Micro Four Thirds lenses will one day be able to autofocus on fast moving targets as well as DSLRs, but I think it is only a matter of time. Professional video cameras can do this; it's just a matter of engineering a solution for stills cameras.

Built-in flash. There is always a big debate about this; should a camera with professional pretensions have built-in flash? You do of course get the equivalent of a built-in flash bundled with the camera and it can also be used as a wireless multi-channel remote flash commander. So I am not really sure how important this issue is.

Underwater housings. Olympus already produces a PT-EP08 underwater housing for the E-M5 and has a track record of producing housings for most system camera models. Independents also make housings for the E-M5, like Nauticam, for example. In fact there is lots of support for underwater use of CSCs.